Imagine a 2-year-old who greets you with a huge smile, offering a toy. Now here’s another child who regards you gravely and hides behind his parent’s leg. How do you feel about these two children? If you’re like most people, you think of the first child as social and the second as reserved or, as everyone tends to interpret, “shy.” From a very young age, we categorize children as one or the other, and we usually privilege the social designation. But this misses what’s really going on with standoffish kids. Many were born with a careful, sensitive temperament that predisposes them to look before they leap. And this can pay off handsomely as they grow, in the form of strong academics, enhanced creativity and even a unique brand of leadership and empathy.

One way to see this temperament more clearly is to consider how these children react to stimuli. When these children are at four months, if you pop a balloon over their heads, they holler and pump their arms more than other babies do. At age 2, they proceed carefully when they see a radio-controlled toy robot for the first time. When they’re school age, they play matching games with more deliberation than their peers, considering all the alternatives at length and even using more eye movements to compare choices. Notice that none of these things — popping balloons, toy robots, matching games — has anything to do with people. In other words, these kids are not antisocial. They’re simply sensitive to their environments.

But if they’re not antisocial, these kids are differently social. According to the psychologist Elaine Aron, author of the book Psychotherapy and the Highly Sensitive Person, 70% of children with a careful temperament grow up to be introverts, meaning they prefer minimally stimulating environments — a glass of wine with a close friend over a raucous party full of strangers. Some will grow up shy as well. Shyness and introversion are not the same thing. Shy people fear negative judgment, while introverts simply prefer less stimulation; shyness is inherently painful, and introversion is not. But in a society that prizes the bold and the outspoken, both are perceived as disadvantages.

Yet we wouldn’t want to live in a world composed exclusively of bold extroverts. We desperately need people who pay what Aron calls “alert attention” to things. It’s no accident that introverts get better grades than extroverts, know more about most academic subjects and win a disproportionate number of Phi Beta Kappa keys and National Merit Scholarship finalist positions — even though their IQ scores are no higher. “The glory of the disposition that stops to consider stimuli rather than rushing to engage with them is its long association with intellectual and artistic achievement,” observes science writer Winifred Gallagher. “Neither E=mc² nor Paradise Lost was dashed off by a party animal.”

Children with an alert, sensitive temperament also pay close attention to social cues and moral principles. By age 6, they cheat and break rules less than other kids do — even when they believe they won’t be caught. At 7, they’re more likely than their peers to be described by parents and caregivers as empathetic or conscientious. As adults, introverted leaders have even been found to deliver better outcomes than extroverts when managing employees, according to a recent study by management professor Adam Grant of the Wharton School of the University of Pennsylvania, because they encourage others’ ideas instead of trying to put their own stamp on things. And they’re less likely to take dangerous risks. Extroverts are more likely than introverts to get into car accidents, participate in extreme sports and to place large financial bets.

But we wouldn’t want to live in a world composed entirely of cautious introverts either. The two types need each other. Many successful ventures are the result of effective partnerships between introverts and extroverts. The famously charismatic Steve Jobs teamed up with powerhouse introverts at crucial points in his career at Apple, co-founding the company with the shy Steve Wozniak and bequeathing it to its current CEO, the quiet Tim Cook. And the three-time Olympic-gold-winning rowing pair Marnie McBean and Kathleen Biddle were a classic match of dynamic firecracker (McBean) and steely determination (Biddle).

The ideal scenario is when those two toddlers — the one who hands you the toy with the smile and the other who checks you out so carefully — grow up to run the world together.